init.c

内核linux2.4.20,可跟rtlinux3.2打补丁 组成实时linux系统,编译内核

extern void sun_serial_setup(void);
extern void cheetah_ecache_flush_init(void);

static unsigned long last_valid_pfn;

void __init paging_init(void)
{
	extern pmd_t swapper_pmd_dir[1024];
	extern unsigned int sparc64_vpte_patchme1[1];
	extern unsigned int sparc64_vpte_patchme2[1];
	unsigned long alias_base = phys_base + PAGE_OFFSET;
	unsigned long second_alias_page = 0;
	unsigned long pt, flags, end_pfn, pages_avail;
	unsigned long shift = alias_base - ((unsigned long)KERNBASE);
	unsigned long real_end;

	set_bit(0, mmu_context_bmap);

	real_end = (unsigned long)&_end;
	if ((real_end > ((unsigned long)KERNBASE + 0x400000)))
		bigkernel = 1;
#ifdef CONFIG_BLK_DEV_INITRD
	if (sparc_ramdisk_image)
		real_end = (PAGE_ALIGN(real_end) + PAGE_ALIGN(sparc_ramdisk_size));
#endif

	/* We assume physical memory starts at some 4mb multiple,
	 * if this were not true we wouldn't boot up to this point
	 * anyways.
	 */
	pt  = phys_base | _PAGE_VALID | _PAGE_SZ4MB;
	pt |= _PAGE_CP | _PAGE_CV | _PAGE_P | _PAGE_L | _PAGE_W;
	__save_and_cli(flags);
	if (tlb_type == spitfire) {
		__asm__ __volatile__(
	"	stxa	%1, [%0] %3\n"
	"	stxa	%2, [%5] %4\n"
	"	membar	#Sync\n"
	"	flush	%%g6\n"
	"	nop\n"
	"	nop\n"
	"	nop\n"
		: /* No outputs */
		: "r" (TLB_TAG_ACCESS), "r" (alias_base), "r" (pt),
		  "i" (ASI_DMMU), "i" (ASI_DTLB_DATA_ACCESS), "r" (61 << 3)
		: "memory");
		if (real_end >= KERNBASE + 0x340000) {
			second_alias_page = alias_base + 0x400000;
			__asm__ __volatile__(
		"	stxa	%1, [%0] %3\n"
		"	stxa	%2, [%5] %4\n"
		"	membar	#Sync\n"
		"	flush	%%g6\n"
		"	nop\n"
		"	nop\n"
		"	nop\n"
			: /* No outputs */
			: "r" (TLB_TAG_ACCESS), "r" (second_alias_page), "r" (pt + 0x400000),
			  "i" (ASI_DMMU), "i" (ASI_DTLB_DATA_ACCESS), "r" (60 << 3)
			: "memory");
		}
	} else if (tlb_type == cheetah) {
		__asm__ __volatile__(
	"	stxa	%1, [%0] %3\n"
	"	stxa	%2, [%5] %4\n"
	"	membar	#Sync\n"
	"	flush	%%g6\n"
	"	nop\n"
	"	nop\n"
	"	nop\n"
		: /* No outputs */
		: "r" (TLB_TAG_ACCESS), "r" (alias_base), "r" (pt),
		  "i" (ASI_DMMU), "i" (ASI_DTLB_DATA_ACCESS), "r" ((0<<16) | (13<<3))
		: "memory");
		if (real_end >= KERNBASE + 0x340000) {
			second_alias_page = alias_base + 0x400000;
			__asm__ __volatile__(
		"	stxa	%1, [%0] %3\n"
		"	stxa	%2, [%5] %4\n"
		"	membar	#Sync\n"
		"	flush	%%g6\n"
		"	nop\n"
		"	nop\n"
		"	nop\n"
			: /* No outputs */
			: "r" (TLB_TAG_ACCESS), "r" (second_alias_page), "r" (pt + 0x400000),
			  "i" (ASI_DMMU), "i" (ASI_DTLB_DATA_ACCESS), "r" ((0<<16) | (12<<3))
			: "memory");
		}
	}
	__restore_flags(flags);
	
	/* Now set kernel pgd to upper alias so physical page computations
	 * work.
	 */
	init_mm.pgd += ((shift) / (sizeof(pgd_t)));
	
	memset(swapper_pmd_dir, 0, sizeof(swapper_pmd_dir));

	/* Now can init the kernel/bad page tables. */
	pgd_set(&swapper_pg_dir[0], swapper_pmd_dir + (shift / sizeof(pgd_t)));
	
	sparc64_vpte_patchme1[0] |= (pgd_val(init_mm.pgd[0]) >> 10);
	sparc64_vpte_patchme2[0] |= (pgd_val(init_mm.pgd[0]) & 0x3ff);
	flushi((long)&sparc64_vpte_patchme1[0]);
	
	/* Setup bootmem... */
	pages_avail = 0;
	last_valid_pfn = end_pfn = bootmem_init(&pages_avail);

#ifdef CONFIG_SUN_SERIAL
	/* This does not logically belong here, but we need to
	 * call it at the moment we are able to use the bootmem
	 * allocator.
	 */
	sun_serial_setup();
#endif

	/* Inherit non-locked OBP mappings. */
	inherit_prom_mappings();
	
	/* Ok, we can use our TLB miss and window trap handlers safely.
	 * We need to do a quick peek here to see if we are on StarFire
	 * or not, so setup_tba can setup the IRQ globals correctly (it
	 * needs to get the hard smp processor id correctly).
	 */
	{
		extern void setup_tba(int);
		setup_tba(this_is_starfire);
	}

	inherit_locked_prom_mappings(1);
	
	/* We only created DTLB mapping of this stuff. */
	spitfire_flush_dtlb_nucleus_page(alias_base);
	if (second_alias_page)
		spitfire_flush_dtlb_nucleus_page(second_alias_page);

	__flush_tlb_all();

	{
		unsigned long zones_size[MAX_NR_ZONES];
		unsigned long zholes_size[MAX_NR_ZONES];
		unsigned long npages;
		int znum;

		for (znum = 0; znum < MAX_NR_ZONES; znum++)
			zones_size[znum] = zholes_size[znum] = 0;

		npages = end_pfn - (phys_base >> PAGE_SHIFT);
		zones_size[ZONE_DMA] = npages;
		zholes_size[ZONE_DMA] = npages - pages_avail;

		free_area_init_node(0, NULL, NULL, zones_size,
				    phys_base, zholes_size);
	}

	device_scan();
}

/* Ok, it seems that the prom can allocate some more memory chunks
 * as a side effect of some prom calls we perform during the
 * boot sequence.  My most likely theory is that it is from the
 * prom_set_traptable() call, and OBP is allocating a scratchpad
 * for saving client program register state etc.
 */
void __init sort_memlist(struct linux_mlist_p1275 *thislist)
{
	int swapi = 0;
	int i, mitr;
	unsigned long tmpaddr, tmpsize;
	unsigned long lowest;

	for (i = 0; thislist[i].theres_more != 0; i++) {
		lowest = thislist[i].start_adr;
		for (mitr = i+1; thislist[mitr-1].theres_more != 0; mitr++)
			if (thislist[mitr].start_adr < lowest) {
				lowest = thislist[mitr].start_adr;
				swapi = mitr;
			}
		if (lowest == thislist[i].start_adr)
			continue;
		tmpaddr = thislist[swapi].start_adr;
		tmpsize = thislist[swapi].num_bytes;
		for (mitr = swapi; mitr > i; mitr--) {
			thislist[mitr].start_adr = thislist[mitr-1].start_adr;
			thislist[mitr].num_bytes = thislist[mitr-1].num_bytes;
		}
		thislist[i].start_adr = tmpaddr;
		thislist[i].num_bytes = tmpsize;
	}
}

void __init rescan_sp_banks(void)
{
	struct linux_prom64_registers memlist[64];
	struct linux_mlist_p1275 avail[64], *mlist;
	unsigned long bytes, base_paddr;
	int num_regs, node = prom_finddevice("/memory");
	int i;

	num_regs = prom_getproperty(node, "available",
				    (char *) memlist, sizeof(memlist));
	num_regs = (num_regs / sizeof(struct linux_prom64_registers));
	for (i = 0; i < num_regs; i++) {
		avail[i].start_adr = memlist[i].phys_addr;
		avail[i].num_bytes = memlist[i].reg_size;
		avail[i].theres_more = &avail[i + 1];
	}
	avail[i - 1].theres_more = NULL;
	sort_memlist(avail);

	mlist = &avail[0];
	i = 0;
	bytes = mlist->num_bytes;
	base_paddr = mlist->start_adr;
  
	sp_banks[0].base_addr = base_paddr;
	sp_banks[0].num_bytes = bytes;

	while (mlist->theres_more != NULL){
		i++;
		mlist = mlist->theres_more;
		bytes = mlist->num_bytes;
		if (i >= SPARC_PHYS_BANKS-1) {
			printk ("The machine has more banks than "
				"this kernel can support\n"
				"Increase the SPARC_PHYS_BANKS "
				"setting (currently %d)\n",
				SPARC_PHYS_BANKS);
			i = SPARC_PHYS_BANKS-1;
			break;
		}
    
		sp_banks[i].base_addr = mlist->start_adr;
		sp_banks[i].num_bytes = mlist->num_bytes;
	}

	i++;
	sp_banks[i].base_addr = 0xdeadbeefbeefdeadUL;
	sp_banks[i].num_bytes = 0;

	for (i = 0; sp_banks[i].num_bytes != 0; i++)
		sp_banks[i].num_bytes &= PAGE_MASK;
}

static void __init taint_real_pages(void)
{
	struct sparc_phys_banks saved_sp_banks[SPARC_PHYS_BANKS];
	int i;

	for (i = 0; i < SPARC_PHYS_BANKS; i++) {
		saved_sp_banks[i].base_addr =
			sp_banks[i].base_addr;
		saved_sp_banks[i].num_bytes =
			sp_banks[i].num_bytes;
	}

	rescan_sp_banks();

	/* Find changes discovered in the sp_bank rescan and
	 * reserve the lost portions in the bootmem maps.
	 */
	for (i = 0; saved_sp_banks[i].num_bytes; i++) {
		unsigned long old_start, old_end;

		old_start = saved_sp_banks[i].base_addr;
		old_end = old_start +
			saved_sp_banks[i].num_bytes;
		while (old_start < old_end) {
			int n;

			for (n = 0; sp_banks[n].num_bytes; n++) {
				unsigned long new_start, new_end;

				new_start = sp_banks[n].base_addr;
				new_end = new_start + sp_banks[n].num_bytes;

				if (new_start <= old_start &&
				    new_end >= (old_start + PAGE_SIZE)) {
					set_bit (old_start >> 22,
						 sparc64_valid_addr_bitmap);
					goto do_next_page;
				}
			}
			reserve_bootmem(old_start, PAGE_SIZE);

		do_next_page:
			old_start += PAGE_SIZE;
		}
	}
}

void __init mem_init(void)
{
	unsigned long codepages, datapages, initpages;
	unsigned long addr, last;
	int i;

	i = last_valid_pfn >> ((22 - PAGE_SHIFT) + 6);
	i += 1;
	sparc64_valid_addr_bitmap = (unsigned long *)
		__alloc_bootmem(i << 3, SMP_CACHE_BYTES, 0UL);
	if (sparc64_valid_addr_bitmap == NULL) {
		prom_printf("mem_init: Cannot alloc valid_addr_bitmap.\n");
		prom_halt();
	}
	memset(sparc64_valid_addr_bitmap, 0, i << 3);

	addr = PAGE_OFFSET + phys_base;
	last = PAGE_ALIGN((unsigned long)&_end) -
		((unsigned long) KERNBASE);
	last += PAGE_OFFSET + phys_base;
	while (addr < last) {
		set_bit(__pa(addr) >> 22, sparc64_valid_addr_bitmap);
		addr += PAGE_SIZE;
	}

	taint_real_pages();

	max_mapnr = last_valid_pfn - (phys_base >> PAGE_SHIFT);
	high_memory = __va(last_valid_pfn << PAGE_SHIFT);

	num_physpages = free_all_bootmem() - 1;

	/*
	 * Set up the zero page, mark it reserved, so that page count
	 * is not manipulated when freeing the page from user ptes.
	 */
	mem_map_zero = _alloc_pages(GFP_KERNEL, 0);
	if (mem_map_zero == NULL) {
		prom_printf("paging_init: Cannot alloc zero page.\n");
		prom_halt();
	}
	SetPageReserved(mem_map_zero);
	clear_page(page_address(mem_map_zero));

	codepages = (((unsigned long) &etext) - ((unsigned long)&_start));
	codepages = PAGE_ALIGN(codepages) >> PAGE_SHIFT;
	datapages = (((unsigned long) &edata) - ((unsigned long)&etext));
	datapages = PAGE_ALIGN(datapages) >> PAGE_SHIFT;
	initpages = (((unsigned long) &__init_end) - ((unsigned long) &__init_begin));
	initpages = PAGE_ALIGN(initpages) >> PAGE_SHIFT;

#ifndef CONFIG_SMP
	{
		/* Put empty_pg_dir on pgd_quicklist */
		extern pgd_t empty_pg_dir[1024];
		unsigned long addr = (unsigned long)empty_pg_dir;
		unsigned long alias_base = phys_base + PAGE_OFFSET -
			(long)(KERNBASE);
		
		memset(empty_pg_dir, 0, sizeof(empty_pg_dir));
		addr += alias_base;
		free_pgd_fast((pgd_t *)addr);
		num_physpages++;
	}
#endif

	printk("Memory: %uk available (%ldk kernel code, %ldk data, %ldk init) [%016lx,%016lx]\n",
	       nr_free_pages() << (PAGE_SHIFT-10),
	       codepages << (PAGE_SHIFT-10),
	       datapages << (PAGE_SHIFT-10), 
	       initpages << (PAGE_SHIFT-10), 
	       PAGE_OFFSET, (last_valid_pfn << PAGE_SHIFT));

	if (tlb_type == cheetah)
		cheetah_ecache_flush_init();
}

void free_initmem (void)
{
	unsigned long addr, initend;

	/*
	 * The init section is aligned to 8k in vmlinux.lds. Page align for >8k pagesizes.
	 */
	addr = PAGE_ALIGN((unsigned long)(&__init_begin));
	initend = (unsigned long)(&__init_end) & PAGE_MASK;
	for (; addr < initend; addr += PAGE_SIZE) {
		unsigned long page;
		struct page *p;

		page = (addr +
			((unsigned long) __va(phys_base)) -
			((unsigned long) KERNBASE));
		p = virt_to_page(page);

		ClearPageReserved(p);
		set_page_count(p, 1);
		__free_page(p);
		num_physpages++;
	}
}

#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
	if (start < end)
		printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
	for (; start < end; start += PAGE_SIZE) {
		struct page *p = virt_to_page(start);

		ClearPageReserved(p);
		set_page_count(p, 1);
		__free_page(p);
		num_physpages++;
	}
}
#endif

void si_meminfo(struct sysinfo *val)
{
	val->totalram = num_physpages;
	val->sharedram = 0;
	val->freeram = nr_free_pages();
	val->bufferram = atomic_read(&buffermem_pages);

	/* These are always zero on Sparc64. */
	val->totalhigh = 0;
	val->freehigh = 0;

	val->mem_unit = PAGE_SIZE;
}